Iranian state television aired a documentary claiming that militants detained last month and linked with the Islamic State extremist group had been paid to carry out assaults in Tehran like the ones in Brussels and Paris.

Footage aired on July 4 showed two suspects, identified by noms de guerre, saying they were recruited in Iraq and Syria to plan multiple attacks in Tehran and other big Iranian cities, for which they would receive $1 million.

Two weeks ago, Iranian intelligence authorities said they had foiled a large-scale terrorist attack, arresting 10 militants, and had seized about 100 kilograms of explosive material that was to be used in car bombs and other attacks in busy public places.

Members of Iran's Revolutionary Guard have fought against IS in Iraq in support of Baghdad's Shi'ite-led government. Guard members and volunteers are also fighting against Sunni militants in Syria in support of President Bashar al-Assad.

Iranian security forces announced in May that they had arrested a dozen IS fighters in the east and west of the country and also more than 50 sympathizers who were promoting the group's ideology on the Internet.